Projectile and gun



April 26, 1938. o. LOGAN PROJECTILE AND GUN Original Filed May 23. 1934 mvsmon Orwell Logan IIQVIZNWWNWWWW Patented Apr. 26, 1938 UNITED STATES PATENT OFFICE Application May 23, 1934, Serial nohzzaoza Renewed July 28, 193'! 19 Claims. (01. 42-16) This'invention relates generally to ordnance and is more specifically designed to produce a projectile .for use in guns, of both rifled and smooth bore types, which shall be of less diameter than that of the bore of the gun, but which shall still utilize the full propelling force of the gases generated behind it by the explosive charge or otherwise Liberated when the gun is fired. The invention also comprises a novel type of automatic breech-operating mechanism for breechloading guns, which mechanism can be actuated by such novel form of projectile.

In present usual practice, the projectile is of substantially the same cross sectional area as the bore of the gun, and the energy which is stored up in the projectile by the pressure of the explosive gases on its rear end must be dissipated, from the moment it leaves the muzzle of the gun, in overcoming the air resistance developed by the-passage of a body of this full cross sectional area, in addition to the eifect of gravity and the energy consumed, for rifles, by the rotation of the projectile. It is known that projectiles having flanges adapted to be closed into grooves in the projectile by an inwardly taperin gun barrel have been proposed, to reduce the air resistance during flight.

I propose a projectile having a relatively heavy body, which may be a shell, a bullet or a shot of special design, the maximum cross sectional area of which is substantially less than the minimum cross sectional area of the bore of the gun in which it is to be used. This body is supported centrally in the bore before firing and during the travel of the projectile through the bore, by one or more spacer pieces, relatively light in weight, separably attached to the body or being a part thereof, and removable therefrom by means more fully described, as being an obstacle causing air resistance. These spacer pieces transmit to the body a substantial amount of propelling energy from the pressure of the expanding gases in addition to the pressure impinging on the area of the rear projection of the body alone. The spacer pieces also, in a rifled bore. engage the rifling and rotate the body. The body is provided with shoulders, tapers or frictional areas which permit support, propulsion and rotation of the body by the spacer pieces, or the spacer pieces may be a part of the body. Rearward from each spacer piece, the body is of the size and shape to permitthe spacer piece to be slipped or forced off,'or if it be a part of the body, to be sheared off or rolled inward toward the body.

At a relatively short distance beyond the muzzle of the gun, I propose to place an obstruction having the general form of a press die, which will permit the body of the projectile to pass and continue its flight, but which will intercept the spacer pieces, and remove them from the body, or will roll or fold them back inward toward the body. A screened opening permitting the escape of the expanding gases and for the control and recovery of spacer pieces is proposed for designs in which the spacer pieces are removed from the body.

The best forms of apparatus at present known to me embodying my invention and one modification thereof are illustrated in the accompanying drawing in which Fig. 1 is a longitudinal section of a smooth bore gun barrel with one form of my improved projectile shown in flight therefrom, parts being broken away.

Figs. 2 and 3 are cross sections of Fig. 1 taken 20 on lines 2-'-2, and 3-3 respectively thereon, the taper of element 9 or 29 not being shown.

Fig. 4 is a view similar to Fig. 1 of a slightly modified form, and

Fig. 5 is a similar cross section on line 55 of Fig. 4.

Throughout the drawing like reference characters indicate like parts.

Referring to Fig. 1, the end of the barrel of a smooth bore gun is indicated at I. An annular housing 2 is clamped thereon, as best shown in Fig. 2.- Rods 3', 3, are surrounded by helical compression springs, one of which is shown at 6 as confined between the annular shoulder 4, fastened on a rod 3 and the end of a bore 5, or other pocket, in housing 2.

The ends of these rods 3, 3, projecting beyond the muzzle of the gun carry the stripping die I which is fastened to them by keys, not shown. inserted in keyways .8. A tubular screen 9, which preferably is slightly tapered as shown, has seated in its smaller end the die I and its larger end surrounding the muzzle of the gun. cate ventilating openings in said screen and Ii is a larger discharge opening, also well shown in Fig. 3. v

The projectile is generally indicated at i2 as having an elongated body usually with a pointed head as shown, and, according to my invention, the rear section of the projectile body i8 is of smaller diameter than is the maximum diameter of the forward section i9 forming the point or head of the projectile. i3 is the shoulder formed at the junction of the two sections l8 and I9 and I4 is a combined spacer ring and annular gas l0, l0 indi-- dicated at 33,

check mounted on the rear section of the projectile and seated against said shoulder l3. A second combined gas check and spacer ring I5 is mounted on the reduced diameter projection 20 at the extreme rear end of the projectile and is seated against the annular shoulder around said projection.

In operation of the described device, the projectile, after being discharged from the muzzle of the gun carrying the annular gas checks l4 and 15 with it, will pass through the opening l1 in the die cient diameter to permit the section IQ of the projectile to pass through it but small enough to arrest both of the gas check rings which will be stripped off as indicated in broken lines, and thereafter drop through the discharge opening I I. The stripped projectile will then proceed on its flight as indicated in dot and dash lines-freed from the drag of the wind resistance of the annular gas checks.

The impact of the spacer rings against the die 1 will evidently force said die and the rods 3, 3, toward the right, thus compressing the springs 6, and after their effective momentum ceases the springs will expand, pulling the parts back into the normal position shown in Fig. 1. Obviously, this reciprocating motion produced on each firing of the gun with a projectile of this character can be utilized to operate any desired reciprocating mechanism.

Referring to Figs. 4 and 5, the muzzle end of a rifle gun barrel is shown at 2|, on which is mounted the fixed annular housing 22 in which are screwed spring-carrying rods- 23 each provided with a head 24 on its free end which is located in one of the cylindrical pockets 25 formed in the sliding annular housing 32. Springs such as 26, are also located in these pockets and between the head 24 and the left hand end wall of the pocket, which latter is perforated to permit the rod 23 to pass through it. In Fig. 4, spring 26 is shown completely compressed, while in Fig. 1, spring 6 is shown partly expanded.

21 is a die similar to die 1, mounted in the conical, tubular screen member 29, which has a number of ventilating holes 30, and a larger discharge opening 3l. This screen carries the die 21 at its smaller end, retaining it against expulsion by means of the annular flange 28. At its other and larger end it is connected to housing 32 by the bayonet joint 4| and through said housing 32, springs 26, rods 23 and fixed housing 22, is afforded a reciprocable connection to the gun barrel 2|.

A cylindrical bore in sliding housing 32, is inwhich is open at the rear end and carries the stuffing box 34 through which the tube 38 telescopes intosaid bore. 35 is a bore of similar diameter in the fixed housing 22 through which tube 38 passes and is held therein by means of a driving fit, or otherwise, with its lefthand end connected by union 39 to exterior tube 36 which may be flexible as indicated, and connected to any desired hydraulic mechanism, such as an automatic breech-operating mechanism, not shown, thereby forming with said mechanism a pump which may be filled with oil or other fluid.

42, in Fig. 4, indicates generally the modified form of projectile best adapted for use in rifles. 40, 40 indicate the rifle lands, and preferably the forward annular gas check 44 is made of a diameter such that it will rather lightly engagethe rifle lands and be only slightly grooved thereby, while the rear annular gas check and spacer ring 1, which opening is made of just suffi- 45 is made of larger diameter so'as to fully engage said lands and act as a. gas check rendered as nearly complete as possible under good practice. The forward ring 44 may also be perforated as indicated at 46 also, if found necessary. The stripper die 21 has a central opening 31 suflicient to pass the projectile 42 but small enough to catch and strip off the spacer rings as before described with reference to Fig. 1.

The cooperating action of the differently constructed gas check rings shown in Figs. 1 and 4 may be explained as follows: In Fig. 1, the solid ring l4 seated against the deep shoulder I3 on the projectile is a very effective propelling agent when the charge is exploded, large quantities of passing through the open- 7 ring l5 were solid, very little gas would get by it to drive ring l4 and the projectile might be driven through the latter while movement thereof was retarded by the gun barrel friction and the resistance of the atmosphere in front of it. Consequently, the force of gravity might then slightly depress the forward end of the projectile before it left the gun and the effective range be thereby reduced.

In Fig. 4, thesame results as to preventing the shoving together of the two spacer rings is attained by making the forward spacer ring 44 of such diameter that it encounters little friction from the rifle lands and some of the air in front of it can get by it through the channels between the lands when the ring starts to move quickly. The perforations 46 in it, if used, also facilitate this action. As a result, the forward ring exercises little projecting force on the projectile 42 and the shoulder 43 may be made of slight depth. The main projecting force is exerted by the solid rear ring 45 which is deeply grooved by the rifle lands so as to form as completely effective a gas check as possible.

The advantages I claim for this device are that the projectile body with its spacer pieces can, with a suitable propelling charge, be given energy at the muzzle equal to, or greater than that which may be given to a projectile having the full cross sectional area at the bore, and that after the removal or reduction in diameter of the spacer pieces by contact with the die, the energy remaining in the body of the projectile is'in greater ratio to the air resistance that will be encountered during the flight of this body of relatively small cross sectional area than can be obtained in a projectile of the full size of the bore of the gun. From this, it follows that a higher striking velocity at all ranges less than maximum range, a flatter trajectory, and a greater total range can be had with the proposed device than can be secured with projectiles of full size of bore. I also claim advantage that projectiles of the type proposed may be thrown from guns having cylindrical bores, either rifled or smooth bore, with or without enlarged chambers at the breech, and that the projectile body and spacer pieces may be of relatively low. cost and ease of manufacture.

The projectile may be made in novel and advantageous shapes. The bodymay be longer in proportion to maximum diameter than is now practicable with present designs, without exceeding that weight which would require the maximum allowable gas pressure to propel it at the corresponding usual muzzle velocity. Present practice does not permit any considerable length of the projectile to extend rearward to thereby reduce the volume of the powder'chamber. The design proposed permits an elongation of the projectile back into the powder chamber from the rear of the spacer piece in a cylindrical or boattail or other suitable form of extension, due to the relatively small diameter of the body.

In the present usual practice for rifled guns, the projectile is of a cylindrical form with a pointed head of the general form of an ogive or a cone or the like; the center of gravity of a solid projectile of this form is rearward from the midpoint of length. It is recognized that the center of air resistance against the projectile during flight will vary in reference to the location of the center of gravity, depending on the velocity of the projectile, speed of rotation, air density, and other variable factors, but for the greater part of flight, the center of effective air resistance is forward from the center of gravity, and to avoid tumbling, the projectile must be rotated on its long axis at high speed; the energy expended to rotate it is taken from that which would otherwise give it higher muzzle velocity. In the type of projectile proposed, the shape of the projectile body is independent of any requirement relating to direct contact with the bore of the gun, such contact being supplied by the spacer pieces, and instead of the length of substantially cylindrical shape now forming the rear or central part and used to guide the projectile. through the bore, a tapering or ogival or paraboloid or like form may be used to reduce the air resistance and to bring the center of gravity of the projectile farther forward of the center of effective air resistance, thus reducing the tendency to tumble, which in turn reduces the rotative speed required, thereby reducing the energy absorbed by the resistance of rifling grooves suitable-for high rotative speed of projectile overgrooves for lower rotative speed, and leaving that difference in energy available for increase of muzzle velocity of the projectile.

The foregoing relates to rifled guns; for guns of relatively low muzzle velocity, the projectile may be designed to place the center of gravity farther ahead of the center of effective air resistance at all velocities from that at the muzzle to state of rest, obviating the necessity for rotation of the projectile body and the rifling of bore, giving an increase in muzzle energy available for translation that would otherwise be absorbed in rotation.

In present practice, the projectile contacts the bore of the gun and the material of the projectile, or of the jacket or band where the projectile is so provided, is limited to those materials soft enough to enter the rifling grooves and hard enough to require the projectile to be guided in rotation by the grooves without fouling them. In the design I propose, the body of the projectile may be of a material or combinations of materials of any reasonable degree of weight, strength and hardness required for armor piercing or other purpose as may be necessary, without considering the effeet of such material on the bore of the gun.

Ordinarily, Iwould prefer to put on each projectile body two spacer pieces in the general form of rings or washers, the innerdiameter of each being in contact with the projectile body, and the outer diameter in contact with the bore of the gun. While two would be a preferred number of spacer pieces for each body, a greater or lesser number may be used. At least one of the spacer pieces must flt tightly enough on the body and engage the bore closely enough to form a gasseal, and in a rifle, it must engage both body and gun bore with sumcient force to rotate the projectile at the desired velocity. While the general form of spacer piece is indicated as a ring or washer, it may be elongated to form a hollow cylinder, with or without grooves, or for a spacer piece at the rear of the projectile body, it may be disklike without any central opening. preferably with a projection on the forward side shaped to engage the rear end of the body. The material for spacer pieces may be of gliding metal, cupro-nickel, or other material not destructive to the bore of the gun, and where greater strength is required, steel or other strong metals may be plated or otherwise treated to combine strength with an outer surface not readily destructive to the here. I claim as an advantage that the spacer pieces, of a material that is usually expensive in relative cost, are recoverable for re-use after firing.

It is known that projectiles have been designed to be supported within the bore of a gun, and during travel within the bore, but heretofore, such supporting parts, as bands and the like, were designed to remain with the body of the projectile during flight, or to be ruptured by the force of the propelling gases and/or by the centrifugal action of the rotating body and supporting piece or pieces, so that the ruptured or separated supporting parts would be thrown clear of the projectile at some point beyond the muzzle. No design has previously been recorded to control and make useful the'supporting parts and the energy contained in them at firing, as here shown and hereinbefore described. Also it has heretofore been proposed to so design the muzzle of a gun, or a perforated cap construction located immediately on and over the muzzle, as to catch and restrain the flight of a sabot originally positively fastened to the projectile, but adaptedto be torn therefrom by rupture of the connecting part, but such prior projects, if operative at all, would be subject to destructive action by the gases of the explosion, whereas according to my invention, the stripper for the rings frictionally mounted on the body of the projectile is spaced away from the gun muzzle at a distance sumcient to remove it from the destructive action of the muzzle blast, thereby permitting its successful operation throughout the discharge of successive projectiles and also rendering it possible to attach it to the barrel of existing guns without changing in any way the standard muzzle construction or conformation.

Having described my invention, I claim:

1. -As a new article of manufacture a subcaliber projectile having an elongated body with two separate and mutually independent, substantially flat rings mounted thereon each of slight rings being frictionally secured to the body so that they will not be stripped rearwardly therefrom by air resistance, friction or inertia-lag arising during the movement of the composite projectile described forwardly through and out of such gun barrel, but will be stripped off rearwardly by any resistances to the flight of such body beyond such gun muzzle substantially in excess of that presented by the external atmosphere over and above any propulsive effect on said rings produced by muzzle blast.

2. An article of manufacture such as defined in claim 1 in which the rear one of said rings has perforations extending through it in directions substantially parallel to the axis of the projectile body.

3. An article of manufacture such as defined in claim 1 in which the forward one of said rings has perforations extending through it in directions substantially parallel to the axis of the projectile body.

4. An article of manufacture such as defined' in claim 1 in which said projectile body has .its head section of larger diameter than its rear section, one of said rings-being mounted on said rear section and seated against the shoulder formed by the juncture of said two body sections.

5. An article of manufacture such as defined in claim 1 in which said projectile body has its head section of larger diameter than its rear section, one of said rings being mounted on said rear section and seated against the shoulder formed by the juncture of said two body sections, while the other is mounted on a short projection at the rear end of said rear section and seated against the annular shoulder surrounding said projection.

6. An article of manufacture such as defined in claim 1 designed for use in rifles, the forward ring on which has its perimeter just large enough to lightly engage the rifle lands, while its rear ring has a perimeter large enough to fully engage said lands when the projectile is fired from the gun and thereby function as a gas check.

7. A mechanism for stripping sabots from subcaliber projectiles adapted for positive but detachable connection to a gun barrel but spaced away from the muzzle thereof axially of the gun bore far enough to permit gases expanding radially therefrom to escape freely, said stripper mechanism comprising a stripper die having a perforation large enough to permit the main body of a given subcaliber projectile to pass through it, but small enough to engage any such sabot and stop further forward flight thereof.

8. An apparatus such as defined in claim 7 combined with a reticulated tube adapted to extend from the muzzle of such gun to said die and surround the path of any projectile passing through both.

9.-An apparatus such as defined in claim 7 combined with a reticulated tube surrounding the path of such projectile, adapted to extend from the muzzle of such gun to said die, and provided with an opening in its lower wall portion large enough to .permit the stripped sabots to be discharged from said tube interior.

10. An apparatus such as defined in claim 7. in which such stripper is capable of a limited movement along lines parallel to the axis of such gun, combined with a spring normally forcing it toward the muzzle thereof.

11. An apparatus such as defined in claim '7, in which such stripper is capable of a limited movement along lines parallel to the axis of such gun, combined with a spring normally forcing it toward the muzzle thereof and pump operatively connected to said die.

12. An apparatus such as defined in claim 7, in which such stripper is capable of a limited movement along lines parallel to the axis of such gun, combined with a spring normally forcing it toward the muzzle thereof and a reciprocable mechanism operatively connected to said die.

13. A mechanism for stripping sabots from subcaliber projectiles adapted for positive but detachable connection to a gun barrel and spaced away from the muzzle thereof axially of the gun bore far enough to permit gases expanding radially therefrom to escape freely, said stripper mechanism comprising a die mounted in bearings permitting it to have a limited amount of motion in a zone substantially beyond that of the muzzle blast from said gun and having a perforation large enough to permit the main body of said projectile to pass through it, but small enough to engage any such sabot and be thereby set in motion.

14. An article of manufacture such as defined in claim 1 designed for use in rifies in which one of said rings has a. perimeter just large enough to lightly engage the rifle lands, while the other has a perimeter large enough to fully engage said lands and serve as a gas check when the projectile is fired from the gun.

15. An apparatus such as defined in claim 7 combined with means located intermediately of said die and the gun muzzle for recovering any such sabot after the same has been stripped from the main body of such projectile.

16. An apparatus such as defined in claim 7 combined with yielding pressure means adapted to allow said die to be momentarily moved slightly further away from the muzzle of said barrel by the impact of any such sabot and to thereafter return it to normal position, whereby any destructive tendency of such impact on said stripper mechanism is materially reduced.

17. An apparatus such as defined in claim 7 combined with yielding pressure means adapted to allow said die to be momentarily moved slightly further away from the muzzle of said barrel by the impact of any such sabot and to thereafter return it to normal position, whereby any destructive tendency of such impact on-said stripper mechanism is materially reduced, and a power device adapted to be energized by such retraction of said die.

18. As a new article of manufacture a subcaliber projectile having an elongated body, the contour of which is divided into a plurality of sections each of circular cross sectional outline and all having a common axis and progressively diminishing in their exterior diameters as the rear end of such projectile is approached, together with a plurality of substantially fiat rings each of slight thickness relative to its internal diameter frlctionally secured one to each of such body sections, except the one forming the projectile head, and each resting against the shoulder formed by the rear end of the next larger section, at least one of said rings having an exterior perimeter of such diameter that when grooved by the lands of a rifle barrel of predetermined diameter it will serve as a gas check for such projectile when fired from such gun.

19. The combination, with a mechanism for stripping sabots from subcaliber projectiles adapted for positive connection to the exterior of a gun barrel at a distance from the mumle there- 7 of sumcient to render it substantially immune from injury by the muzzle blast which comprises a stripping 'diehaving a perforation just large enough to permit the main body of a given subcaliber projectile to 'pass through it, but small enough to engage any such sabot and-stop further flight thereof, of a projectile cooperating therewith having an elongated body just small enough to pass through said die and a sabot of considerably larger diameter detachably mounted thereon.

' ORWELL LOGAN. I 

